Open Access Open Access  Restricted Access Subscription or Fee Access

Evaluation of Gamma Radiation Induced DNA Damage in Bombyx mori, using Single Cell Gel Electrophoresis (Comet Assay)

Ashok R, Shetty N.J, Hariprasad T.P.N


Bombyx mori (B. mori) is the model insect used in the present study, which is commercially important compared to other Lepidopterans. Eggs of late embryonic stage (7 day old) of B. mori were exposed to different doses of gamma radiation to study the extent of DNA damage using comet assay which is a rapid technique to study the genotoxic effects. Test samples were exposed to varied doses of radiation (100, 250, and 400 Gy) to evaluate the genotoxicity at 60, 90 and 120 min post irradiation. The results showed that Olive tail moment (OTM) in all the samples had significant linear increase (P≤0.05) in DNA damage. The maximum DNA damage was observed 60 min post irradiation to all the doses while the maximum damage was at 400 Gy (60.1±3.52) compared to the control. The damage was found to be gradually decreasing at higher time points of 90 and 120 min for all the doses, indicating the activity of DNA repair mechanisms. We also observed that, the intensity of the DNA damage aggravated with increase in dose and time post irradiation. The outcome of this study can be used as an important biomarker for environmental risk assessment.


Bombyx mori, Gamma radiation, embryonic stage, comet assay, olive tail moment

Full Text:



Zhao P, Li YQ, Hiroshi F, Yutaka B, Xiang ZH. Purification,Characterization and cloning of achymotrypsin inhibitor (Cl-9) from the haemolymph of the silkworm, Bombyxmori. JProtein.2005; 26(5):349–357.

FASSET. Framework for Assessment of Environmental impact. Luxemburg: European Community; 2001; 1–48.

Sparrow AH. Types of ionizing radiations and their cytogenetic effects. In:Symposium on mutation and plant breeding, Publications.Washington, DC: National Academy of sciences, National Research Council.1961;891: 55–119.

Fellows PJ.Food processing Technology: Principles and practices.4th Edn. Elsevier; 2018;279–280. ISBN 978008101907

Hasan M, Khan AR. Control of stored products pests by irradiation. Integr Pest Manag.1998;3:15–29.

Tothova A, Marec F. Chromosomal principle of radiation-induced F1 sterility in Ephestiakuehniella (Lepidoptera:pyralidae). Genome.2001; 44(2):172–184.

LaChance LE. The induction of dominant lethal mutations in insect by ionizing radiation and chemicals-as related to the sterile-male technique of insect control. Genetics of insect vectors of disease.1967;617–650.

WolfKW, Nova KK, Marec F. Kinetic organization of metaphase I bivalents in spermatogenesis of Lepidoptera and Trichoptera species with small chromosome numbers. J Heredity.1997; 79:135–143.

Lee RF, Steinert S. Use of the single cell gel electrophoresis/comet assay for detecting DNA damage in aquatic (marine and fresh water) animals. Mutat Res.2003; 544(1):43–64.

Tice RR, Agurell E, Anderson D, Burlinson B, et al. Single cell gel/comet assay: Guidelines for in vitro and in vivo genetic toxicology testing. J Environ Mol Mutat.2000; 35(3):206–221.

Singh NP, McCoy MT, Tice RR, Schneider EL. A simple technique for quantitation of low levels of DNA damage in individual cells. J Exp Cell.1988;175(1):184–191p.

Bajpayee M, Panday A.K, Parmar D, Mathur N, Seth PK, Dhawan A. Comet assay responses in human lymphocytes are not influenced by the menstrual cycle:a case study in healthy Indian females. Mutat Res.2005;565(2):163–172.

PremilaChanu O, Ibotombi N. Effects of 60C Gamma radiation on eggs of tasar silkworm, Antheraeaproylei (Lepidoptera). J Exp Scien.2011; 9:19–23.

Subramanya G, Sreeramareddy G. Isolation of a Mutant line with Shorter Larval Duration by Induction of Mutations in the Silkworm Bombyxmori L. Indian J Exp Bio.1982; 20(2): 139–141.

Murakami A. Variation in radio sensitivity during the early developmental stage of the silkworm egg. Ann Rep Nat Inst Genetics.1965;16:401–404.

Astaurov BL.Artificial mutations in the silk-worm (BombyxmoriL.). Genetica. 1935;17:


Hirobe T. Utilization of gamma-ray effects in the field of silkworm breeding. Indian JGenet. 34A. Proc2nd General Congress SABRAO, New Delhi.1973; 1974: 224–228.

Ikenaga M, Kondo S. Comparative studies of mutation frequencies induced by 32P treatment and gamma irradiation the male silkworm. Mutat Res.1965; 2(6):534–543.

Shigematsu H, Takeshita H. Effect of gamma ray irradiation in embryonic stages on the cell proliferation of silkglands and the silk formation in Bombyxmori L. (Lepidoptera: Bombycidae). Appl Ent Zool. 1968;3(1): 52–54.

Hasan MD, Todoriki S, Miyanoshita A. Detection of gamma radiation-induced DNA damage in maize weevil, Sitophiluszeamais (Coleoptera:Curculionidae) assessed using the comet assay. Int J Rad Biol.2008;84(10):815–820.

Kameya H, Miyanoshita A, Imamura T. Assessment of gamma ray-induced DNA damage in Lasiodermaserricorneusing the comet assay. Radiat PhysChem.2012;81(3):316–321.

Revankar PR, Shyama SK. Genotoxic effects of monocrotophos, an organophosphorus pesticide, on an astuarine bivalve, Meretrix ovum. Food Chem Toxicol.2009;47(7):1618–1623.

SalehaBanu B, Danadevi K, Rahman MF. Genotoxic effect of monocrotophos to sentinel species using comet assay. Food Chem Toxicol.2001;39(4):361–366.

Sowmithra K, Shetty NJ, Jha SK, Chaubey RC. Evaluation of genotoxicity of the acute gamma radiation on earthworm Eiseniafetida using single cell gel electrophoresis technique (Comet assay). MutatRes. 2015;794:52–56.

Shetty V, Shetty NJ, Ananthanarayana SR, Jha SK, Chaubey RC. Evaluation of gamma radiation-induced DNA damage in Aedesaegypti using the Comet assay. J Toxicol Ind Health.2017;33(12): 930–937.


  • There are currently no refbacks.

Copyright (c) 2020 Research & Reviews: A Journal of Toxicology